微波辅助液液微萃取-气相色谱-质谱分析蔬菜、水果中的多种拟除虫菊酯残留

Determination of Pyrethroid Insecticide Resdues in Vegetable and Fruit by Microwave-assisted Liquid-Liquid Microextraction and Gas Chromatography-Mass Spectrometry

将微波辅助萃取同液液微萃取技术相结合 ,利用气相色谱 质谱分析技术 ,结合时间编程 选择离子检测模式 ,开发了一种简捷、实用、回收率高的蔬菜、水果中多种拟除虫菊酯残留的检测技术。该技术同当前执行的国标方法相比 ,有机溶剂用量少 ,操作简便 ,提取液无须严格净化便可进行GC/MS分析 ,大大提高了分析速度。经基体标准加入回收实验 ,除联苯菊酯外 ,其他 9种菊酯的 10ng/g的加样回收率均在 75 %以上 ,且在国标要求的最大残留限量附近有良好的线性关系 ,能满足当前蔬菜。

A simple, rapid and reproducible multiresidue analytical method for the determination of pyre-throids at low nanogram levels in vegetable and fruit is described. Preconcentration was achieved by treating the sample with microwave-assisted extraction (MAE) and liquid-liquid microextraction (LLME) using n-hex-ane. Pyrethroid quantification was achieved by gas chromatography (GC) with mass spectrometry (MS) de-tection in electron impact (EI) and time program-selected ion monitoring mode (EI/SIM). The recovery effi-ciencies of the tested pesticides yield vary from 75% to 110% at a fortification level of 10 ng/g. And their relative standard deviations (RSD) vary between 4.5% and 10.7%. Detection limit of each compound varies between 0.01 and 0.1 ng/g without any additional clean-up, with linear ranges from 0.5 to 2500 ng/g.